Psoriasis is the most common T helper cell type 1 (Th-1) autoimmune disease, affecting over 2% of the adult population. Similar to other major chronic illnesses, psoriasis is associated with significant decrements in health related quality of life. Psoriasis is characterized by thick, red, scaly skin plaques which can be localized or widespread and an inflammatory arthropathy in some patients. For over 30 years, investigators have suggested that psoriasis may be associated with an increased risk of myocardial infarction, however, there have been no studies evaluating this association using population-based methods and multivariable analysis to control for potential confounding variables. We have developed compelling preliminary data that psoriasis may be an independent risk factor for developing MI. Increasing evidence has linked Th-1 inflammatory pathways to the development of atherosclerosis and ultimately, myocardial infarction, suggesting that the pathophysiology of psoriasis may confer an independent risk for myocardial infarction. In fact, other Th-1 diseases, such as rheumatoid arthritis, have been shown to be independent risk factors for myocardial infarction. We propose to conduct a series of population-based cohort studies to determine if patients with psoriasis have a higher prevalence of cardiovascular risk factors, poorer control of cardiovascular risk factors, and an increased risk of myocardial infarction, stroke, and cardiovascular mortality compared to patients without psoriasis. Studying the relationship between psoriasis, cardiovascular risk factors, and cardiovascular outcomes will have important implications as to our understanding of the relationship between inflammatory diseases and myocardial infarction and will have potentially important public health implications for the care of the over 7 million US patients with psoriasis.